Chain block hoist



March 27, 1956 SMlTH 2,739,789

CHAIN BLOCK HOIST 4 Sheets-Sheet 1 Filed July 1, 1950 March 27, 1956 R. E. SMITH CHAIN BLOCK HOIST 4 Sheets-Sheet 2 Filed July 1, 1950 March 27, 1956 R. E. SMITH CHAIN BLOCK HOIST 4 Sheets-Sheet 3 Filed July 1, 1950 w. f w i ZKZ ELL 5 JHVEJYZUP fiqz oh [ism 2212 March 27, 1956 s ri'H CHAIN BLOCK HOIST 4 Sheets-Sheet 4 Filed July 1, 1950 015 229 ,&\%

United States Patent O CHAIN BLOCK HOIST Ralph E. Smith, Muskegon Heights, Mich., assignor to Manning, Maxwell & Moore, Inc., Muskegon, Mich, a corporation of New Jersey Application July 1, 1950, Serial No. 171,603

3 Claims. (Cl. 254-171) The present invention relates to a chain block hoist and more particularly to a hand actuatable, easily operable, compact chain hoist.

The chain block hoist of the present invention is of very compact design making possible the utilization of smaller overall dimensions than those hoists generally available at the present time. This compactness results from the employment of a unitary load and driving shaft which provides a very small driving pinion and which carries a relatively small load sprocket. All operating parts of the hoist are housed within a balanced frame construction which prevents exposure of the operating parts of the hoist to the elements, and/or to dirt, dust and other foreign matter in the environment in which the hoist is employed.

The closed and balanced frame construction of the hoist operating parts provide chain guides for both the hand chain and the load chain to prevent jamming or gagging of the chain, even if the hoist is utilized in a horizontal position. The present invention provides several different types of hand wheel guides each of which insures smooth, dirt-free hand wheel chain operation. The hoist is provided with a Weston-type load brake located at one extremity of the unitary shaft and with an idler and ring gear unit at the other end of the shaft in mesh with a pinion gear formed on the shaft itself and effective to drive a load sprocket located intermediate the load brake and the drive gearing and mounted concentrically on the shaft.

One feature of the present invention resides in the anti-friction mounting of the load brake ratchet, thereby permitting the load carried by the load chain sprocket to be lowered with less effort than is necessary with those devices now generally available. The anti-friction mounting of the ratchet may also be employed with a springurged cam block brake, as well as with a ratchet pawltype brake.

Another feature of the present invention is the provision of the idler gears of the drive gearing with shafts which are journaled in the balanced frame. More particularly, this latter feature includes the provision of idler gear shafts carried by a frame end closure plate at one end and by an annular ring positioned within the closed frame and receiving the other end of the idler gear shafts. The idler gears themselves are mounted on the idler gear shafts for free rotation by means of antifriction hearings to provide easily manually operable load hoisting and lowering operations.

An additional feature of the present invention is the utilization of a shear pin on the load chain itself to prevent damage to the hoist gearing upon the lowering of a load to the extreme position permitted by the length of the load chain.

A further feature of the present invention resides in the provision of an improved means for mounting a load hook on the load chain. This means includes a pair of separable chain hook blocks adapted to retain the butt end of a hook in a recess cooperatively defined by the 2,739,789 Patented Mar. 27, 1956 ICC block sections and receiving the load chain terminal ends between a pair of pad-shaped lugs formed in the block sections. A simple cylindrical sleeve is employed to secure the separable block sections in cooperative relationship. This economical lower hook securing means effectively eliminates bending fatigue stresses at the point of hook attachment, which stresses have been a frequent cause of hook failure in the prior art.

It is, therefore, an important object of the present invention to provide an improved, compact chain block hoist having a balanced frame substantially enclosing all operable parts of the hoist.

Another important object of the present invention is to provide an improved chain block hoist having a unitary load shaft and drive shaft journaled within a substantially closed frame and provided with a Weston-type load brake having a load ratchet mounted on the shaft through an anti-friction bearing to facilitate work lowering operation of the hoist.

It is a further important object of the present invention to provide an improved chain block hoist operable through a gearing arrangement to elevate and lower a workpiece and provided with means actuatable upon the subjection of the gearing arrangement to a predetermined load to prevent damage to the gearing arrangement.

Still another important object of the present invention is to provide an improved chain block hoist having a manually operable load chain and a hook for securing a workpiece to the load chain, the hook being secured to the load chain through a separable hook block which is not subject to bending fatigue, even upon repeated use.

Yet another important object of the present invention is to provide a chain block hoist having a substantially closed frame journaling therein a unitary load shaft and driving shaft providing the driving pinion of an idler and ring gearing arrangement for driving a sprocket concentrically mounted on the shaft and provided With an improved load chain guide and stripper means.

Still a further important object of the present invention is to provide a chain block hoist having a balanced frame construction substantially enclosing all of the operating parts of the hoist and providing a hand chain guide for preventing jamming and gagging of the hand chain even during horizontal use of the hoist.

An additional object of the present invention is to provide a chain block hoist having a load brake utilizing spring-urged cam means for preventing slippage of a hoist load elevated by the hoist.

Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying drawings.

On the drawings:

Figure l is a side elevational view of a chain blocl: hoist of the present invention;

Figure 2 is a greatly enlarged sectional view, with parts shown in elevation, taken along the plane II-II of Fig. l

Figure 3 is a sectional view, with parts shown in elevation, taken along the plane III-III of Fig. 2;

Figure 4 is a fragmentary sectional view, with parts shown in elevation, taken along the plane IV-IV of Fig. 2;

Figure 5 is a greatly enlarged sectional view, with parts shown in elevation, takenalong the plane V--V of Fig. 1;

Figure 6 is a sectional view, with parts shown in elevation, taken along the plane VI-VI of Fig. 5;

Figure 7 is an exploded sectional view similar to Fig. 5;

Figure 8 is a fragmentary sectional view, similar to Fig. 2, of a modified form of chain block hoist;

Figure 9 is a fragmentary sectional view, with parts shown in elevation, similar to Fig. 8 showing another modified form of the invention; and

Figure 10 is a sectional view taken along the plane X-X of Fig. 9.

As shown on the drawings:

In Figure 1, reference numeral 10 refers generally to a chain block hoist of the present invention including a manually operable hand wheel chain 11 for elevating and lowering a workpiece (not shown) carried by a hook assembly 12 secured to a load chain 13.. The hoist 10 is adapted to be secured to a support member, such as an overhead beam, hook or the like, by an upper block hook 14.

Frame structure As best shown in Figures 2 and 3, the hoist 10 includes a central frame 15 which is generally cylindrical in outline and which is provided with a pair of radial complementary walls 16 and 17, respectively, extending across the interior of the frame to divide the frame into a plurality of interior recesses including a central downwardly opening recess 18 and oppositely directed end recesses 19 and 20, respectively. Each of the recesses is closed by an end cover plate 21 and 22, respectively, secured thereto by suitable means, as by screws 22a. The end cover plates are of dished configuration for cooperation with the end recesses 19 and to provide enlarged end chambers at each axial end of the frame 15.

That portion of the frame 23 overlying the central recess 18 is apertured as at 24 to receive therethrough a threaded depending boss 25 formed integrally with the upper hook 14 and extending into the central recess 18 to threadedly receive thereon a nut 26.. The hook 14 is thus rotatably secured to the frame 15.

The hoist is of single shaft design and a unitary load and driving shaft 28 is provided to project axially of the frame 15 through the recesses 18, 19 and 20 and into closely spaced clearance relation with the end cover plates 21 and 22. That end of the shaft 28 projecting into the end recess 20 is journaled by suitable means, as by a ball bearing 29 carried by interior frame wall 17 at the center thereof.

Load brake structure The free shaft end 30 extending into the recess 26 is provided with axially extending splines 31 mating with interior spline formed on a load brake hub 32 for a Weston-type load brake 33.

The load brake hub 32 is provided with an exterior screw threaded periphery 34 extending axially of the brake 33 into threaded engagement with corresponding interior threads 35 formed in a chain Wheel hub 36 which is provided with a rearward radially extending flange 37 providing a plane radially enlarged forward face against which a hand chain Wheel 38 is secured by suitable means, as by screws 39 threadedly retained by corresponding apertures formed in the flange 37 and passing through registering apertures formed in the separable halves 38a and 38b of the hand chain wheel 38. it will be appreciated that the hand chain wheel is provided with peripheral pockets and projections as is conventional in the art for receiving thereabout the hand wheel chain 13 adapted for manually energizing the chain block hoist.

That surface of the flange 37 opposing that receiving thereagainst the hand chain wheel 38 abuts a load brake ratchet 4%} having peripheral ratchet teeth 41 formed thereabout and cooperating with a ratchet pawl 42 as best shown in Figure 4. The ratchet pawl 42 is pivoted at one end, as at 43, to a pivot leg 44 formed integrally with the frame 15. The free end of the ratchet pawl 42 is urged into engagement with the load brake ratchet teeth 41 by suitable means, as by a compression spring 45 confined between and guided by an embossrnent 46 on the ratchet pawl 42 and ascrew 47 threadedly retained by the upper wall of the frame 15 in position to overlie the free end of the ratchet pawl.

contacting the Wall '17 and its inner race bearing against The load brake ratchet 40 cooperates with a load brake flange 48 to confine therebetween a multi-layer friction facing 49. The load brake flange 48 is secured to a radially enlarged embossment 50 formed on the load brake hub, and anti-friction means, such as a roller bearing 51, is interposed between the load brake ratchet 40 and the hub embossment 50. Thus the ratchet is carried by the hub with the bearing 51 accommodating free relative rotation therebetween upon the subjection of either of the members to a rotation-preventing load. it will be noted that the chain wheel hub 36 and the load brake hub 32 are capable of relative threaded axial movement, with the provision of a brake stop lug 52 retained at the terminal end 30 of the shaft 28 by means of a snap ring 53 preventing separation of these members from the shaft.

Load sprocket gearing That end 55 of the shaft 28 opposing the end 30 and projecting into the recess 19 is journaled within an antifriction hearing, such as roller bearing 56 having its outer race secured within a peripheral wall 21a formed in the end cover plate 21 and its inner race contacting the shaft adjacent the extreme end thereof.

immediately adjacent the shaft terminal end 55, there is formed a peripheral gear or pinion surface 57 which is in mesh with a plurality of idler gears 53. The idler gears 58 are mounted upon idler shafts 59 through the medium of anti-friction bearings, such as roller bearings 69. accommodating free rotation of the gears 53 upon their shafts. Each idler gear shaft is provided with a central axial extension 61 seated within a corresponding recess 62 formed in the cover plate 21 while the opposing end of the idler gear shaft is provided with an eccentric axial extension 63 which is positioned within a corresponding aperture 64 formed in an annular ring 65 surrounding each of the extensions 63. It will be seen that the relative eccentricity of the shaft extensions 61 and 63 prevents rotation of the shaft 59 with the idler gears 57, thereby preventing any unwarranted bearing and/ or shaft wear and loss of function. An annular idler shaft spacer washer 66 is interposed between the cover plate 21 and each gear 58 and between each gear 58 and the annular plate 65 to prevent axial play of the idler gears 58 while at the same time accommodating rotation thereof.

The idler gears 58 are enclosed by a ring gear 67, having internal gear teeth 68 meshing with the idler gear teeth, thus forming a uniplanar pinion, ring and idler gearing assembly. Actually, the ring gear 67 is formed as an axial extension of a gear sprocket 69 having a radial Web portion 70 joining the ring gear portion 67 to a hub portion 71 having an axial projection 72 journaled by suitable means, as by a ball bearing '73 in the frame wall 16. The bearing 73 has its outer race contacting an extension 74 on the wall 16 concentric with and surrounding a corresponding portion of the shaft 25, while the inner race of the bearings '73 is fitted onto the axial extension 72 of the sprocket gear. The sprocket gear extension 72 is provided with internal splines engaging corresponding external splines formed on an axial extension 75 of a load chain sprocket 76.

The load chain sprocket 76 is axially apertured to receive the shaft 28 and is freely rotatable thereon. it will be seen that driving of the shaft 23 by means of the load brake assembly 33 hereinbefore described will drive the idler or planetary gears 58 from the pinion 5'7. This driving of the idler gears in engagement with the sprocket gears 69 will cause a corresponding co-rotation of the load chain sprocket 76 upon the shaft 28. The sprocket 76 is rotatably supported upon the shaft 23 for rotation relative thereto by means of the bearings 73 for the sprocket gear 69 hereinbefore described and by means of a second anti-friction bearing 77 having its outer race the load chain sprocket 76. The relatively small load chain sprocket 76 is provided with peripheral radially inwardly extending recesses 78 for receiving the load chain 13 with sprocket projections 79 between the recesses 73 for positive interlocking engagement with the load chain.

Shear pin structure The frame is provided with a radially inwardly projecting boss 80 aligned with the sprocket 76 and having an open bottomed intermediate slot 81 therein, as best shown in Figure 3 of the drawings. The slot 81 is adapted to receive a terminal link 13a of the load chain 13 and a shear pin 82 is provided to extend transversely across the slot 81. The shear pin 82 includes a screw head 83 provided with peripheral threads for engaging the corresponding aperture 84 formed in the frame 11 and the shank of the screw head 83 is provided with axially spaced reduced portions 85 on either side of an enlarged central portion 86 receiving the terminal link 13a thereabout. A terminal shank portion 87 is snugly received by a recess 88 formed in the boss 80 and communicating with the slot 81.

It will be seen that if the load chain 13 were entirely extended and an additional load were placed thereon exceeding the shearing strength of the reduced portions 85 of the pin 82, these portions would shear, thereby preventing damage to the gearing and/or remaining portions of the apparatus.

Load chain guide and stripper assembly Also as seen in Figures 2 and 3, a combined load chain guide and stripper 99 is provided, the guide and stripper comprising complementary sections 91 secured together by suitable means, as by nuts and bolts 92 threaded through registering apertures formed in the sections. Each section 91 comprises a generally annular member having a central aperture 93 adapted to snugly receive the load chain sprocket therein.

The circumference of each of the sections 91 is provided with oppositely directed lugs 94 having plane upper surfaces adapted to abut the undersurfaces of corresponding lugs 95 projecting radially inwardly from the peripheral walls of the frame 15 (Figure 3). Each guide section 91 is also provided with additional radially projecting lugs 96 having lower surfaces for engaging the corresponding upper surfaces of the lugs 95, so that the lugs 94, 95 and 96 cooperate to position each section 91 of the chain guide 90 within the frame 15 and to retain the chain guide therein against rotative movement. The lugs 94 are spaced between the corresponding portions of the lugs 95 so that a limited amount of relative radial movement between the sections 91 and the frame is accommodated.

The cooperating sections 91 when secured together define an interior recess 97 aligned with the chain-receiving sockets 78 of the chain sprocket 76 to form a cover for the sockets 78 and to effectively guide the links of the chain load 13 therethrough.

Movement of the chain guide 90 axially of the shaft 28 is prevented by closely spaced relation of the lower portion of the chain guide 90 between the walls 16 and 17 of the frame 15 as illustrated in Figure 2. This lower portion of each chain guide section 91 carries a complementary chain stripper member 98 each having an upstanding web portion 99 closely confined between the complementary guide sections 91 and terminating in an upper arcuate surface 100 closely underlying the sockets 78 of the load chain sprocket 76. Each chain stripper section 98 is provided with a lateral flange 101 which is secured to the lowermost portion of the corresponding chain guide section by suitable means, as by screws 102 threadedly retained by registering tapped holes in the chain guide sections 91.

Load hook attachment assembly In Figures 57, inclusive, there is illustrated the means for attaching the load hook 12 to the load chain 13. The terminal link 13b at that end of the chain 13 opposite to the link 13a hangs freely from the load chain sprockets 76 hereinbefore described. The link 13b is positioned within a hook block assembly including a pair of complementary hook blocks 111. Each block 111 is of semi-cylindrical outline and is provided with an outer peripheral recess 112, and a lower semi-cylindrical recess 113 extending through the bottom thereof and communicating with an upper interior radially enlarged recess 114. The upper portion of each block is provided with an arcuate upwardly opening recess 115 adapted to receive a portion of the link 13b and having a central radially inwardly extending leg 116 cooperating with the recess 115 to define a lower arcuate aperture 117 having the same center of curvature and a slightly larger radius than that of the link 13b. As best shown in Figure 7, the hook 12 is provided with a reduced neck 118 joining the hook proper to an upper enlarged terminal boss 119.

To assemble the hook 12 to the chain 13, it is only necessary to position the chain and hook as shown in Figure 7 and to enclose the same with the blocks 111 with the hook boss 119 fitting within the recess 114 and the neck 118 projecting from the block through the joining aperture 113. The terminal link 13b of the chain 13 is seated within the recess 115 with the extreme end of the link being positioned within the arcuate recess 117. A generally cylindrical sleeve 120 is telescopically received by the block 111 to fit thereabout in the peripheral grooves 112. A pair of snap or lack rings 121 are next positioned within a radially extending relatively short groove 122 to overlie the sleeve 120 and to retain the same in peripherally engaged position about the block 111.

The inwardly extending abutting block lugs 116 cooperate to provide a pad snugly seatable within the terminal link 13b, and it will be seen that substantially no bending load is imposed upon the lugs due to their relatively short radial lengths and their snug fit about the chain links.

Those skilled in the art will also appreciate the possibility of economically manufacturing the means for securing the hook to the chain inasmuch as the separable block sections 111 may be made of a steel or similar forging, so that a very minimum amount of machining is necessary and the sleeve 120 is preferably formed of seamless steel tubing, so that a snug telescopic fit of the sleeve and separable sections is provided without the necessity of expensive machining or other finishing operations. The only force to which the blocks 111 are submitted is a shearing force of the lugs 116 and of the lower portion of the block underlying the hook boss 119. These shearing forces may be easily borne by a steel forging or the like.

Operation The operation of the hoist hereinbefore described will be readily appreciated by those skilled in the art. As

hereinbefore described in connection with the load brake assembly 33, movement of the hand chain 11 in a lifting direction will engage the load brake friction facings 49 between the ratchet 40 and the load brake flange 48 to drive the shaft 28 through the load brake hub 32 splined thereon. Rotation of the shaft 28 will be imparted through the pinion surface 57 to the idler gears 53 and then to the sprocket gear 69. Inasmuch as the sprocket gear 69 is splined to the load chain sprocket '76, rotation of the load sprocket within its journals 73 and 77 will be effected regardless of rotation of the shaft 28.

The combined chain stripper and guide 9i), also hereinbefore described, fits very snugly about the load chain sprocket 76 to provide an efiective chain guiding and stripping assembly, while at the same time the cooperating lugs 94, 95 and 96 on the sections 91 and on the frame 15 retain the assembly 90 in desired position, while still accommodating pulling of the chain about the sprocket in a direction inclined to the vertical. In addition, it will benoted that the end cover plate 22 closing the end recess 20 effectively serves as a chain guide for the hand chain 11 lapped about the hand chain wheel 38. It will be noted that the cover plate 22 is secured to the frame by means of the screws 22a so as to be readily removable to permit inspection and/ or repair of the hand chain, hand chain wheel, load brake or load brake ratchet, as may be desired. The other end cover plate 21 is likewise removably secured to the frame by suitable means, and the removal of this cover plate provides easy access to the entire gearing of the hoist without the necessity of disassembly of the sprocket and/or chain guide and stripper assembly. Further, the mounting of the idler gear shaft 61 on the end cover plate 21 prevents the necessity of providing separate mounting means for the idler gear shaft, while the mounting ring 65 receiving the eccentric idler shaft extensions 63 prevents rotation of the idler shaft while at the same time providing a simple, readily assembled means for securing the free ends of the idler shafts.

Although only a single bearing means is provided to directly journal the shaft within the frame, the sprockets within the frame, and the sprocket gear within the frame, respectively these three bearing means are interrelated and co-supporting so that both the shaft and the sprocket are effectively supported at axially spaced points within the frame in direct load-bearing relation thereto. In addition, it will be seen that a counterbalanced frame construction is provided by the mounting of the load brake assembly and the gearing assembly on opposing sides of the central recess, while the load chain is directly aligned vertically with the hook 14, so as to be in direct load bearing relation thereto.

When it is desired to lower a workpiece supported by the load bearing chain 13, it is only necessary to reverse the direction of rotation of the hand chain wheel by proper manipulation of the hand chain 11. This movement, of course, will attempt to reverse the direction of movement of the load chain ratchet, which movement is prevented by the ratchet pawl 42 in contact therewith. The supported load itself will tend to turn the brake through the medium of the flange 48, but this movement will merely force the load brake hub flange 48 into tighter engagement with the friction facings 49, thereby preventing accidental slippage of the load.

To lower the load, upon the reversal of direction of movement of the hand chain wheel from a lifting direction, this effort will be applied to the hub 35 to back the hub away from the stationary ratchet 40, thereby releasing the load and allowing the same to descend. Thus, although the ratchet is held in position, the hub 32 is rotated relative thereto and this rotation is facilitated by the anti-friction bearings 51 interposed therebetween, thus reducing the lowering effort heretofore necessary which, in the absence of the anti-friction bearings, must overcome surface friction between the ratchet 40 and the hub 32.

The modified form of Figure 8 In the modified form of chain block hoist shown in Figure 8 of the drawings, identical reference numerals of this figure refer to identical portions of the apparatus, and it will be seen that the main difference resides in the provision of a more shallow end recess 20 in the frame 15 and the interposing of an arcuate hand chain guide block 120 between the frame 15 and the end cover plate 22. The hand chain guide block 120 extends axially of the shaft 28 through a distance substantially equal to the axial length of the hand chain wheel 38 and the guide block 120 extends into closely spaced radially aligned relation with the hand chain wheel. The block is radially recessed, as at 121,- intermediate its length to accommodate upstanding lengthsofchain lapped about 8 the hand chain wheel, to thereby permit closer chain guiding relation between the guide and the wheel.

It will also be noted that the load brake of Figure 8 has been slightly modified to illustrate the utility .of a cam-block type brake with the present invention. The concentric hubs 32 and 36 are not threaded in this form, but an enlarged end cap 122 is provided to abut the axial end of the hub 36, and the abutting faces of these members are provided with mating cooperable cam surfaces for effecting axial movement of the hub 36 and ratchet flange, as is well known in the art.

The modified form of Figures 9 and 10 In Figures 9 and 10 of the drawings, still another form of hand chain guide is illustrated. In this form of the invention, the frame 15 is provided with an axial exten sion 125 of substantially the same contour as the guide 120 hereinbefore described in connection with Figure 8 of the drawings. It will also be noted that the lower portion of the frame is provided with an axial extension 126 adapted to receive a fastening means, such as a screw 127, passing through the end cover plate 22 and threadedly retained by the frame extension portion 126. The load brake of this form of the invention is substantially the same as above described in connection with Figure 8.

In Figure 10 there is illustrated a different form of ratchet means for preventing rotation of the load brake under a gravitational load imparted to the load chain. The means takes the form of a plurality of cam blocks 130 pivotally mounted on supporting bosses 131, carried by an adjacent portion of the frame 15 and extending inwardly of the frame in a plane parallel to the axis of rotation of the shaft 28. The cam blocks 130 are each provided with a bottom arcuate cam shoe 132 which extends into surface contact with the smooth circular periphery 133 of a ratchet flange 134, substantially the same as the load brake ratchet 40 hereinbefore described in connection with the embodiment of Figures 1-7, but in which the ratchet teeth 42 have been eliminated.

A coiled torsion spring 135 serves to urge the cam shoe 132 of each of the cams 130 against the periphery 133 of the ratchet flange 134. One end 136 of the spring 135 contacts the inner periphery 137 of the frame 15, while the other end 138 of the spring engages a portion of the cam shoe itself.

It will be seen that when the ratchet flange 134 is moved in a counterclockwise direction, as indicated by a directional arrow 140, free rotation of the ratchet is accommodated by the cam shoes 132 slipping over the surface of the surface 133. However, upon rotation in the opposite direction of the flange 134, the cam shoes 132 are urged into biting contact with the periphery 133 of the flange to prevent rotation thereof. It will be readily appreciated by those skilled in the art that lifting movement of the hand wheel chain 11 causes rotation of the flange 134 in a counterclockwise direction, which rotation is accommodated by the cam shoes as hereinbefore described, while attempted rotation in a clockwise direction under a load is prevented by engagement of the cam shoes 132 with the periphery 133.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

1. In a chain block hoist having a frame provided with an interior wall defining an open ended chamber, a cover plate for closing said open ended chamber, a shaft journaled by said frame and said cover plate for rotation, a pinion on said shaft, a plurality of idler gear shafts each having a first axial extension retained by said cover plate and an oppositely directed second axial extension eccentric with respect to said first extension, an apertured ring receiving said second axial extensions, said cover plate and said ring supporting said shafts in radially spaced relation to said pinion, a plurality of idler gears mounted on said idler gear shafts, anti-friction means interposed between each of said idler gears and the corresponding idler gear shaft, a drive sprocket having internal gear teeth meshing with said idler gears, and a sprocket journaled in said frame and adapted to be driven for rotation by said gear sprocket.

2. In a chain block hoist having a frame defining an open ended chamber, a driving shaft journaled by said frame and carrying a pinion thereon in said chamber, and a sprocket also journaled by said frame, a cover plate closing said chamber, a plurality of idler gear shafts each having oppositely directed relatively eccentric axial extensions, one of which is supported by said cover plate and the other of which projects into the interior of said chamber, means retaining said other extensions to prevent rotation of said shafts, a plurality of idler gears meshing with said pinion and each supported by one of said shafts, and a ring gear in mesh with said idler gears and drivingly connected to said sprocket.

3. In a chain block hoist, a driving shaft, a uniplanar pinion-ring-and-idler gearing assembly located at one end of said shaft for actuation thereby comprising a driving pinion on said shaft, a plurality of uniplanar idler gears displaced radially of said shaft and in mesh with said pinion, and a ring gear meshing with said idler gears and having an axially extending boss drivingly connected to a load sprocket; and means for rotating said shaft comprising a hub mounted on said shaft for rotation therewith and having a flange projecting radially therebeyond, a ratchet concentric with said hub and axially spaced from said flange, a hand chain wheel adapted for manual References Cited in the file of this patent UNITED STATES PATENTS 609,939 Kincaid Aug. 30, 1898 917,965 Regan Apr. 13, 1909 1,572,001 Dotzert Feb. 9, 1926 1,576,986 Mullen Mar. 16, 1926 1,903,218 Knight Mar. 28, 1933 1,913,861 Stahl June 13, 1933 1,919,754 Sejersen July 25, 1933 2,231,416 Stahl Feb. 11, 1941 2,324,000 Johnston July 13, 1943 2,325,917 Parker et al. Aug. 3, 1943 2,375,719 Wirkkala May 8, 1945 2,453,581 Moore Nov. 9, 1948 2,493,727 Parker et a1 Jan. 3, 1950 2,623,731 Kamlukin Dec. 30, 1952 FOREIGN PATENTS 992,778 France July 11, 1951 

